A female (KU 38830), having a total length of 1390 (1180 + 210), from 5 mi. ESE Seoul conforms to descriptions of _anomala_ in being uniformly pale brown above and in having indistinct dark smudges on the sides; the ventral surface is whitish having indistinct dark smudges, brown spots at the ends of each ventral, and the posterior edge of each ventral brown. A male (KU 40125), measuring 1090 (890 + 200) in total length, from 5 mi. E Seoul, is pale brown above and lacks markings on the anterior part of the body. Indistinct dark markings occur at midbody, whereas the posterior quarter of the body and tail have well-defined black bands on a buff background. The black bands posteriorly are arranged in pairs; each pair of bands is separated by two and a half to three scales, whereas the bands of each pair are separated by only one and a half scales. The ventral surface has an obscure marbled pattern. Our largest specimen, a male (UMMZ 113454) having a total length of 1488 (1230 + 258), from the Central National Forest, resembles KU 40125, except that pale brown blotches (29 on body, one blackish on neck) and dark lateral spots occur anteriorly on the body. Another female (KU 38860, body length, 970) from 4½ mi. W Chip´o-ri, our northernmost locality of record, has a fairly distinct pattern dorsally. The 30 dark brown, black-edged blotches that are separated by a buff background are not arranged in pairs (as in KU 40125); the dorsal blotches sometimes alternate with small lateral blotches. The ventral surface is marbled throughout. Two males from the Central National Forest, having total lengths of 1105 (920 + 185) and 830 (690 + 140), generally resemble one another in having the head and neck dark brown or blackish and the anterior part of body dark brown, but discernibly blotched. The posterior part of the body and tail of each bears well-defined blotches (dark brown or black) with buffy interspaces; the dorsal blotches are sometimes arranged in pairs. The ventral surface of each is marbled throughout. These two males are noteworthy in that the pattern anteriorly is obscure, but the ground color is dark, not pale as in the two specimens from the vicinity of Seoul. =Agkistrodon halys brevicaudus= Stejneger _Agkistrodon blomhoffii brevicaudus_ Stejneger, Bull. U. S. Nat. Mus., 58:463, July 22, 1907 (type locality, Pusan, Korea). _Agkistrodon halys brevicaudus_, Okada, A catalogue of vertebrates of Japan, p. 103, 1938. _Specimens examined_ (12).--Central National Forest, near Pup´yong-ni, 4 (KU); 3 mi. NW Chip´o-ri, 2 (KU); 16 mi. NE Mosulp´o, Cheju Do, 1 (UMMZ); 5 mi. E Seoul, 1 (UMMZ); 6 mi. E Seoul, 2 (KU); 7 mi. ESE Seoul, 1 (KU); 7 mi. NNE Sogwi-ri, Cheju Do, 1 (UMMZ).